A variety of nanostructures have been envisioned for use in industries ranging from structural materials to electronic devices. For example, carbon nanotubes have been highlighted as novel sources for future nano-electronics. Carbon nanotubes may have high aspect ratios with small diameters, 103 times higher electronic current carrying capacity (109 A/cm2) than that of the noble metals, two times higher thermal conductivity (6600 W/mK) than that of pure diamond, and they may be ballistic conductors at room temperature over many microns. Carbon nanotubes may be either metallic or semiconducting depending on the way in which the graphene sheet is rolled to form the desired nanotube. Both metallic and semiconducting carbon nanotubes have potential for widespread applications, ranging from ultra-low resistance materials, transparent conductors, and electrical interconnects in the case of metallic carbon nanotubes. Semiconducting carbon nanotubes are desired for field-effect transistors applications.
Carbon nanotubes are usually produced by synthetic protocols as mixtures of all electronic types. Therefore, the separation and electronic sorting of carbon nanotubes remains a substantial barrier to widespread electronic and optical applications of these and similar materials.
Accordingly, improved materials and methods are needed.